Means for cooling gun barrels



March 22,- 1938. R. c. COUPLAND 2,112,144

MEANS FOR COOLING GUN BARRELS Filed July 28, 1932 I I $2 s M W -53 ii QI Inventur L; m Richard E.Eu up1am:1

Patented Mar. 22, 1938 UNITED STATES PTENT FFiQE Richard C. Coupiand,Norfolk, Va., assignor tothe Secretary of War of the United States ofAmerica Application July 28, 1932, Serial No. 625,436

7 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) The invention described herein may be manufactured and usedby or for the Government for governmental purposes, without the paymentto me of any royalty thereon.

This invention relates to means for cooling gun barrels.

The purpose of the present invention is to provide an air-cooled jacketfor gun barrels which will be effective in conducting heat from thebarrel, and which may in part be conveniently ex tended to the rear endof the barrel.

A further object is to provide a jacket that is inexpensive and light inWeight and one that may be readily attached to and removed from the un.

To these and other ends, the invention consists in the construction,arrangement and combination of elements described hereinafter andpointed out in the claims forming a part of this speci- 20 fication.

A practical embodiment of the invention is illustrated in theaccompanying drawing, wherein: Fig. l is a longitudinal sectional viewof the improved jacket mounted over a gun barrel.

Fig. 2 is a similar view of a jacket of a smaller type.

Referring to the drawing by numerals of reference there is shown aportion of the receiver 5 of a machine gun whose barrel 5 isreciprocally 30 supported at its rear end in a bearing l carried by thetrunnion plates 8 of the receiver.

The jacket consists of a sleeve 9 having a relatively thick wall taperedtowards the front in accordance with the plotted curve showing the heatof the barrel along its length when the gun is being fired. The sleeveis preferably formed of a light metal such as aluminum or a magnesiumalloy.

Within the sleeve is a tube Ill, preferably of 40 bronze and adapted tohave a sliding fit on the barrel ii. The sleeve is pressed or cast onthe tube in order to obtain a close fit under high temperatures.

In the rear end of the sleeve a counterbore ll receives a socket memberi2 of a stronger and harder metal such as steel. The socket member isthreaded onto the projecting end l3 of the tube I i! and is held againstrotation by one or more set-screws i4 engaging the sleeve. The rear faceof the socket member is flush with the rear face of the sleeve. Thesocket member is provided internally with threads l5 whereby it isconnected to threads 95 formed externally on the forward portion of thebearing 1.

On the front end of the sleeve a steel insert ll fitting over the frontend of the tube and attached thereto is held against rotation by one ormore set-screws l8 engaging the sleeve. This insert projects beyond thesleeve and provides for attachment of the customary recoil check and 5flash hider.

A block i9 consisting of a metal similar to that of which the sleeve isformed, is placed underneath the bearing 7 between the opposite trunnionplates 8 and is mounted on pins or rivets 20 securing the trunnionplates 8 to the receiver 5. The block extends forwardly as far as thefront edge of the upper brackets 2! of the trunnion plates 8.

When the jacket is mounted on the forward portion of the bearing itextends practically to the projectile chamber 22 of the barrel. Thejacket and block l9 radiate heat to a sufficient extent to maintain thebarrel below the critical tempera ture of the metal of the barrel.During extended firing a more or less constant temperature will prevailand as a result a uniform pattern of shots will be obtained.

In Fig. 2 the jacket is similar to that of Fig. 1 with the exception ofthe sleeve to whose wall thickness is reduced.

I claim:

1. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end inserted in the bearing, a metal block underneath 0the bearing, a jacket over the barrel including a bronze tube, a sleeveover the tube formed of a light metal such as aluminum or magnesium,

a steel socket member in the rear end of the sleeve providing formounting the jacket on the forward end of the bearing, and said sleevetapered toward its front end in accordance with the heat curve of thegun barrel when in operation.

2. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end inserted in the bearing, a metal block underneaththe bearing, a jacket over the barrel including a bronze tube, a sleeveover the tube formed of a light metal such as aluminum or magnesium, asteel socket member in the rear end of the sleeve providing for mountingthe jacket on the forward end of the bearing.

3. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end inserted in the bearing, a metal block underneaththe bearing, a jacket over the barrel including a tube and a sleeve overthe tube, said tube and sleeve being of a light metal having a highdegree of thermal conductivity, and a socket member of a heavier metalfixed in the rear end of the sleeve and providing for attachment of thejacket on the forward end of the bearing.

4. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end inserted in the bearing, a jacket over the barrelincluding a tube and a sleeve over the tube, said tube and sleeve beingof a light metal having a high degree of thermal conductivity, and asocket member of a heavier metal fixed in the rear end of the sleeve andproviding for attachment of the jacket on the forward end of thebearing.

5. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end inserted in the bearing, a heat-conducting blockunderneath the bearing and a heat-conducting jacket embracing all of thebarrel forwardly of the bearing and mounted on the forward end of thebearing.

6. In a gun, a receiver, a gun barrel projecting from the receiver, ajacket fitting over the barrel and attachable to the receiver, saidjacket including a relatively thin tube and a relatively thick sleeveover the tube, said tube and sleeve being of a light metal and having ahigh degree of thermal conductivity.

7. In a gun, a receiver, a bearing carried by the receiver, a gun barrelhaving its rear end supported in the bearing, and a separate blockunderneath and in contact with the bearing, said block being of amaterial of higher thermal conductivity than the material of thebearing.

RICHARD C. COUPLAND.

